UC San Diego

There is a commonly accepted paradigm in viral ecology that lytic dynamics are the default pathway for viruses and that lysogeny is a refuge for viruses when lytic dynamics are unlikely to succeed (e.g., when host densities are low). This was established early in the development of the field of viral ecology (Chapter 2). Here, an analysis of viral and microbial counts and viral metagenomes collected from across the Pacific and Atlantic Oceans (Chapter 3), as well as an exhaustive literature analysis of published frequencies of mitomycin C inducible cells (a proxy for lysogeny) addition (Chapter 4) shows a lack of support for the established paradigm. Rather, the increased success of lysogenic viruses at high host density is supported, and no significant trends in mitomycin C inducible cells were observed. From the latter study, a hitherto uncharacterized driver of viral dynamics is laid out to guide future studies. Taken together, these analyses suggest that lysogeny becomes increasingly prevalent at high host densities, and that there may be novel drivers of inducibility that can allow viral ecology to transcend traditional drivers like host density and growth rate.